Data/hora: 18/05/2024 10:34:54

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 03/10/2008
Data da última atualização: | 03/10/2008
Autoria: | GRYZIAK, G.; MAKULEC, G.
Título: | Do engineering earthworms and plant diversity influence oribatid mites?
Ano de publicação: | 2008
Fonte/Imprenta: | In: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM.
Idioma: | Inglês

Conteúdo:

Effects of geophagous earthworms on plant growth and yield and on oribatid mites as well, are
still ambiguous, and existing results are often contradictory. This research was aimed at
answering the question: How are abundance and diversity of oribatid mites connected with
plants diversity and activity of soil engineering species (i.e. Aporrectodea caliginosa)?
Two types of experiments were performed:
1. Field mesocosm experiment. In June 2004 six hundred plastic containers (mesocosms,
capacity: 10L), were placed into the ground and sown with grass. One half of mesocosms were
sown with the one species (Festuca rubra), and the second half were sown with a mixture of 8
grass species. After one growing season) 6 individuals A. caliginosa were introduced into half
of the mesocosms in each treatment ? monoculture and mixture. For analysis of oribatid mites
communities soil samples were taken 4 times a year, till November 2006.
At the beginning mites community was dominated by Microppia minus (app. 95%), but it lost its
share. It is noticeable that higher grass production causes higher oribatid mites abundance
although it causes lower diversity. After the introduction of earthworm the substantial differences
in abundance of oribatid occurred: it was higher in mixture with and without earthworms, than in
monoculture.
2. Laboratory experiments. Small, plastic containers (capacity: 1L), filed by earthworm-free soil
(the same soil and prepared in the same way as in the filed experiment) were divided on 2 parts
by metal mesh (2 mm). One earthworm was introduced into inner part in first variant and into
outer in second one. Another variant experiment was: no earthworm and no mesh; earthworm
and no mesh; no earthworm and mesh. Samples from 10 random containers were taken 4
times, after each 30 days. Samples were extracted and collected mites were preserved by
normal methods.
Density of mites was higher in soil without earthworms than in soil with earthworms.
Oribatid mites seem to avoid earthworms. They have low metabolic rate, slow development and
low fecundity. Earthworms and oribatid mites use the same food recourses. Avoidance of
earthworms is adaptive for mites, because they cannot stand competition with earthworms.
This research was granted by Ministry of Science and Higher Education (PL).

Categoria do assunto: | --
Registro original: | Embrapa Florestas (CNPF)
Exemplares: | CNPF - (43794-1) - UPE - PL - -- - CD0305 -  -  - DIS