Data/hora: 02/06/2024 07:19:20

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 18/09/2008
Data da última atualização: | 18/09/2008
Autoria: | CARRERA, N.; BARREAL, E.; BRIONES, M. J. I.
Título: | Seasonal changes of Oribatida communities in a blanket bog.
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:

Peatland soils are estimated to store a third of all terrestrial carbon stocks and they are very
sensitive to climate change. The environmental conditions in these ecosystems (continuous
high precipitation, more than 30 days per annum with risk of frost, frequent cloudiness) have a
strong influence on the activities of their communities (plant and animals). Since temperature
and rainfall are the two variables which are likely to change due to climate change it is critical to
determine the role of soil moisture in interaction with temperature on the below-ground responses
(soil fauna) and on the carbon balance. In this study we report the results for Oribatid mites
which are often the most diverse and numerically dominant arthropods in organic soils. They
predominantly feed on fungi and decomposing plant materials and play a key role in SOM
decomposition and nutrient cycling. The site under investigation was a blanket bog within the
Natural Habitat Sierra of Xistral (Lugo, Spain). Fifteen undisturbed soil cores (10 cm diameter
and 20 cm deep PVC pipes) were taken in winter (February) and summer (June) during three
consecutive years (2003, 2004 and 2005). Cores were sliced horizontally into five 2 cm layers
to a depth of 10 cm and subsamples of every horizontal layer were used for microarthropod
extraction (40 cm2) and moisture content determinations (20 cm2). Invertebrates were preserved
in 70% ethanol and identified to family level. Meteorological data (average monthly temperatures
and rainfall values) for the three years were obtained from the closest meteorological stations.
Results showed the strong sensitivity of these ecosystems to the environmental conditions.
Generally, higher temperatures and low precipitation values registered during the summer months
but year 2005 was notably dry (the driest year of the past 125). The oribatid community at the
site is diverse (19 different families) although only nine families were recorded in all sampling
occasions. In addition, although the majority of their populations seem to be concentrated in the
upper layers (0-2 cm) lower rainfall inputs had a negative effect on their abundances. With a few
exceptions little vertical migration was detected in response to the decrease in moisture and
thus, reflecting their low resistance to drought. We conclude that as a result of these alterations
in oribatid communities, important changes in the decomposition processes as well as food
web stability are anticipated.

Categoria do assunto: | --
Registro original: | Embrapa Florestas (CNPF)
Exemplares: | CNPF - (43616-1) - UPE - PL - -- - CD0305 -  -  - DIS