|
|
Impact of boric acid on Collembola, Protura and Pauropoda in a mountain elm forest in the Šumava National Park, Czech Republic
Rusek, Josef
A field experiment with weak boric acid (50g in 10 L water) was performed around trees of mountain elm (Ulmus glabra) in an Ulmeto-Aceretum forest community, Šumava National Park, to establish the impact of the acid on soil Collembola, Protura and Pauropoda. Boron should improve the physiological condition of the elms and their resistance to graphiosis. Soil samples (10 cm2 and 10cm deep) were taken around 10 trees on 15th July 1984. Eight of these trees (A-F, I, H) were without any previous treatment, whereas two trees (G, K) had received an application of boric acid eight months before. Immediately after the July sampling, boric acid was applied around five trees (A-E). Eight days later, a second sampling was done around trees A-E and control trees F and I. Five samples were taken around each tree at each sampling - 50 samples at the first sampling and 35 samples the second time. The soil fauna was extracted in a high-gradient apparatus, sorted into higher taxonomic groups and determined to species level in Collembola, Protura and Pauropoda. The community data and their differences before and after boric acid treatment were statistically evaluated using Sorensen's Average Linkage Method. The studied community was composed of 44 Collembola, 6 Protura and 2 Pauropoda species. The density of Collembola around the trees reached 8000-36 800 ind.m-2. The Shannon-Wiener index of diversity was high (H=3,077). Isotomiella minor, Protaphorura s-vontoernei and Parisotoma notabilis were the most dominant species. The first two species were euconstant and constant, while the third one (C=49,94) was almost euconstant. All other species were recedent or subrecedent. Twenty-one species of Collembola were present eight days after the treatment around trees A-E. Five recedent species occurred in lesser numbers after the treatment. Mesaphorura tenuisensillata became constant and P. notabilis recedent. The differences in collembolan density around individual trees before and after the treatment were not significant. Also, Sorensen's Average Linkage analysis did not show differences in this mesofauna community betweeen the treated and untreated trees.
|
guest ::
