Data/hora: 08/06/2024 04:45:04

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 22/09/2008
Data da última atualização: | 22/09/2008
Autoria: | LINDO, Z.
Título: | Patterns of diversity in arboreal and terrestrial oribatid mite communities.
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:

Oribatid mites (Acari: Oribatida) are typically the dominant component of the microarthropod
fauna in forest floor systems. Oribatid mites are also species rich and numerically dominant
in temperate and tropical forest canopies, where arboreal communities are distinct from
forest floor communities, contribute significantly to overall forest biodiversity, and are
functionally important components of forest ecosystems. Oribatid mites are observed in
many arboreal habitats, including bark and trunks of trees, leaf domatia and stems, conifer
branch tips and needles, epiphytic cover including lichens and moss mats, epiphytic vascular
plants, and in accumulations of organic matter known as suspended soils. Moderate-tohigh
levels of habitat specificity are expected for arboreal species, as habitat heterogeneity
and complexity has been shown to be important in shaping arboreal mite communities; high
oribatid mite species richness is often associated with spatially complex, well-developed
suspended soils. In areas of the North American temperate rainforest, spatially discrete
suspended soils are thought to be interconnected islands through which random movement
actively disperses individuals, yet the initial source pool and dispersal mechanisms of the
resident arboreal fauna assemblages are unknown. I used the suspended soil system in
western redcedar trees in the temperate rainforest on Vancouver Island, Canada to compare
the arboreal (suspended soil) and terrestrial (forest floor) oribatid mite communities, determine
the factors that contribute to arboreal oribatid mite community structure, and elucidate the
dispersal processes and colonizing source pools of the arboreal oribatid mite assemblage.
Sampling methods included collecting substrate core samples, bark scrapings and litterfall,
and observing oribatid mite colonisation of litterbags and artificial canopy habitats. 138
species of oribatid mites were identified within the 1-hectare study area. The amount of
unique arboreal species (20%) suggests that the arboreal oribatid mite community is distinctly
different from the forest floor and not just a random subset of the terrestrial assemblage.
The documented pattern of oribatid mite diversity in this rainforest demonstrated higher
local species richness (alpha diversity) in terrestrial habitats, and greater beta diversity in
arboreal habitats. The factors, which shape canopy oribatid mite communities within arboreal
habitats, are related to habitat availability, moisture limitation and random dispersal events
of individual species. Results further suggest the arboreal oribatid mite community
experiences dispersal limitation associated with physical tree-to-tree dispersal barriers.
However, factors other than physical dispersal barriers, such as aggregation and niche
partitioning, likely also limit the local distribution of species in both arboreal and terrestrial
habitats. The oribatid mite community within suspended soils are formed primarily by dispersal
within the canopy system, with limited colonisation from the forest floor. Dispersal dynamics
within the canopy are crucial to understanding oribatid mite community structure in suspended
soils, yet community composition is also is dependent on environmental tolerances of
individual species at the local scale.

Categoria do assunto: | --
Registro original: | Embrapa Florestas (CNPF)
Exemplares: | CNPF - (43661-1) - UPE - PL - -- - CD0305 -  -  - DIS