Effect of Grazing on the Plant Community of a Southern Brazilian Swamp

Abstract

Swamps have high biological diversity and are the largest producers of biomass. However, such ecosystems are threatened by human activities. This study analyzes the plant community structure of two swamp sites, with and without grazing. A total of 200 sample units with 0.25 m 2 were distributed every 13 m to determine diversity, the Importance Value Index (IVI), and coverage. Fifty species and 18 families were recorded. Luziola peruviana Juss. ex. JF Gmel had the highest IVI, accounting for 62.57% of the relative coverage in cattle-influenced sites. In the portions without cattle, Commelina diffusa Burm.f. had the highest IVI (24.33). The Shannon and Pielou indexes were 2.18 nats.ind.-1 and 0.56, respectively, decreasing to 1.62 nats.ind.-1 and 0.47 in grazing sites. There was less richness in the cattle grazing area, with a single species accounting for a high percentage of coverage, indicating the possible role of grazing on the plant community structure.

Ethnopharmacological study of native medicinal plants and the impact of pastoralism on their loss in arid to semiarid ecosystems of southeastern Iran

“…Since species density, frequency and dominance comprised IVI are sensitive indicators to anthropogenic actives 26 , 27 . Reaction of species to human exploitation can be revealed with comparing IVI with and without exploiting 28 , 29 . Relative loss (RL) index was measured to assess ecological situation of medicinal plants under both nomadic and sedentary pastoral system using changes IVI.…”

Non-utilization Is Not the Best Way to Manage Lowland Meadows in Hulun Buir

“…In addition, the results of community stability calculations also indicated that the community composition at the MG site was more stable than that at the HG site (A lower score indicates a more stable community; therefore, the MG plant community had the highest stability, Supplementary Table 1). In contrast, Spellmeier et al (2019) in swamps of southwestern Brazil showed that grazing reduced plant species richness. Spellmeier et al (2019) selected a test site with naturally high plant richness that was in its native state; the data showed that the species count at that site under non-degraded conditions was much higher than that in the C. meyeriana meadow considered in this study.…”

“…In contrast, Spellmeier et al (2019) in swamps of southwestern Brazil showed that grazing reduced plant species richness. Spellmeier et al (2019) selected a test site with naturally high plant richness that was in its native state; the data showed that the species count at that site under non-degraded conditions was much higher than that in the C. meyeriana meadow considered in this study. In conclusion, our experimental results indicated that UN (enclosure) is not the most appropriate management method for meadows in the long run (Sun et al, 2020).…”