Abstract: Shouqu wetland of Yellow River plays important roles in the ecological security of the lower reaches of Yellow River. By the method of replacing time series with spatial sequence, an investigation was made on the changes of plant species diversity in the process of the natural degradation of the wetland. A co mparison was also made to study the effects of artificial drainage on the plant species diversity. The results indicated that in the degradation process of Shou qu wetland, i.e., from swamp to swamp meadow, to alpine meadow, and to steppe me adow, the dominant plants followed the pattern of hygrophytes being gradually re placed by mesophytes and xerophytes, richness index and diversity index were inc reasing while dominance index was decreasing, and evenness index decreased first and increased then. The species diversity had an overall increasing trend. Afte r artificial drainage, the proportion of poisonous weeds in the plant community increased, resulting in the increase of richness index and diversity index, slig ht decrease of evenness index and dominance index, and gradual decrease of Soren sen index. Artificial drainage made the habitat drying, which provided a chance for some mesophytes to invade, resulting in the increase of diversity index and richness index and the decrease of evenness index. On the whole, artificial drai nage increased the plant diversity in the community, but the increase accompanie d with increasing poisonous weeds, and thus, led the Shouqu wetland degraded int o weed type wetland.

Key words: ecological land, spatial-temporal evolution, Wuhan urban agglomeration, geographically weighted regression