Data/hora: 01/06/2024 10:46:28

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 02/10/2008
Data da última atualização: | 02/10/2008
Autoria: | MENDES, S. M.; RUIZ-CAMACHO, N.; FREITAS, H.; LAVELLE, P.; SOUSA, J. P.
Título: | Bioindicators and biological indexes of soil quality. Improving the application of IBQS index in assessing effects of management practices on Mediterranean areas using soil epigeal macrofauna.
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:

Monitoring soil quality can be done using several approaches, namely through the use of soil
quality indices based on biological indicators. Among these, the ?Indice Biotique de la Qualité
du Sol? (IBQS) uses the concept of indicator species associated to a typology of sites/treatments
under assessment to rank their soil quality. In order to evaluate the application of IBQS
methodology to Mediterranean landscapes, its resolution power and applicability to soil epigeal
macrofauna data, a case-study, implemented in a Portuguese cork-oak forest (?Montado?) was
analysed. Five areas were established following a chronosequence of a disturbance regime
(time since understory clearing), comprising a non disturbed control area plus four areas with
different times since shrub was cut (1 year, 2 years, 3-4 years and 4-5 years); in the same farm,
three more areas were defined: an area with cattle grazing and two areas where the understory
cut residues were incorprated into soil at different times, implying a strong soil mobilization. At
each area, nine pitfall traps were settled, following a nested design. Sampling took place in
Autumn 2003. Biological material was identified to family/order and to species level; when this
was not possible, morphospecies was used.
Over 240 species/morphospecies were identified. When using the traditional IBQS formula,
areas where shrub is incorporated into the soil (the more disturbed areas) presented the highest
IBQS values, followed by areas with traditional ?Montado? use; the lowest value was obtained
for grazing. However, using a correction factor (indicator species contribution for explaining the
variability observed on a PCA) to the formula, developed under this study, IBQS values for areas
representing the traditional and sustainable use of ?Montados? are higher than the ones obtained
for other areas. Regarding the taxonomical discriminatory power of IBQS when calculated based
on data at different taxonomic level, the shift from species to higher taxonomical levels suggested
a loss of resolution, with values calculated at species level allowing a better discrimination
between the different areas.
Overall analysis showed that IBQS is sensitive to the abundance of specific taxa, especially of
opportunistic species, able to reach high abundances in disturbed areas, and originating a
biased ranking of soil quality values. This is a common phenomenon when evaluating pitfall trap
data, what could lead to a strong bias in IBQS values. The application of the developed correction
factor to IBQS formula originates a more ecologically relevant ranking, suggesting that its
application could be useful in bypassing questions arisen from using pitfall data in calculating
IBQS values.

Categoria do assunto: | --
Registro original: | Embrapa Florestas (CNPF)
Exemplares: | CNPF - (43778-1) - UPE - PL - -- - CD0305 -  -  - DIS