Abstract:
In order to reveal plant community composition, interspecific relationship and community stability in the xerophilic zone, the hygrogenetic zone and the ecotone zone of the Jiangxia Wetland in the middle reaches of the Lhasa River Basin. Community composition, diversity, interspecific association and community stability were analyzed by using 105 herbaceous quadrats. The results showed that there were 40 species of plants belonging to 33 genera and 16 families in the xerophytic zone, the ecotone zone and the hygrophytic zone. The species diversity was highest in the xerophytic zone, followed by the hygrophytic zone, and lowest in the hygrophytic zone. The dominant species in the xerophytic zones were
Argentina anserina,
Plantago depressa and
Cynoglossum amabile. The dominant species in the hygrogenetic zone were
Potamogeton natans,
Kobresia pygmaea,
Carex moorcroftii. The dominant species in the ecotone were
K. pygmaea,
C. moorcroftii and
A. anserina. Overall dominant species were
K. pygmaea,
Kobresia robusta,
C. moorcroftii,
A. anserina. There was no significant correlation between the ecotone zone and the hygro-growth zone except for the significant negative correlation between the interspecific associations in the xerophilic zone.
X2 test, Association Coefficient (
AC), Percentage of Common Occurrence (
PC) and Point Correlation Coefficient (
Ф) test showed that the advantages were not strongly associated with each other, and each species was relatively independent. According to the method of community stability analysis improved by Zheng Yuanrun, it was further concluded that the whole community was in an unstable succession stage. During the process of vegetation protection and ecological governance in the Jiangxia Wetland, priority should be given to species with extremely significant positive correlation between species and a high correlation index, as well as similar environmental adaptability such as
Digitaria sanguinalis +
Taraxacum mongolicum、
Plantago depressa +
T. mongolicum、
Astragalus strictus +
D. sanguinalis mixed plant species such as Ma Tang and others serve as pioneer species. At the same time, based on the ecological characteristics of the plants, it is necessary to select a reasonable combination of species for configuration. When the ecological environment improves in the middle stage of succession, main dominant species such as
K. pygmae,
K. robusta,
A. anserina, etc., can be supplemented to improve the interspecies relationships, increase the stability of the community, accelerate the succession process, and promote the vegetation recovery. These measures will be beneficial for the restoration of the plant community in the Jiangxia Wetland and will contribute to the ecological protection and high-quality development of the Lhasa River Basin. The results can provide important basic data for vegetation restoration of wetland ecosystem in the study area
.