| dc.description.abstract | The survey of soil mites was carried out with two main objectives: (i) To determine the
effect of land use types and seasons on abundance and diversity of soil mites and (ii) to
establish the effects of soil chemical parameters (C, N and pH) on the abundance and
diversity of soil mites.
The study sites were along a gradient of LVT at Embu and Taita Districts of Kenya. The
LUT studied were: maize-based, coffee, napier. horticulture, tea (agro-ecosysterns).
fallow and eucalyptus forest, Meru oak forest, natural forest pine forest, and cypress
forest (forest ecosystems). Internationally agreed guidelines on sampling design were
adopted. Sampling was carried out on a 6 Km2 transect covering most of the LVT on
every benchmark site. Soil sampling was done in two seasons between October 2007 and
Apri1200S. The top Scm of soil together with litter was collected to extract soil mites and
analyse soils for total Carbon (C), total Nitrogen (N) and pH. Soil mites were extracted
using a modified Berlese- Tt;llgren funnel. The Mites were identified to families level
using published identification Keys.
Soils from forest ecosystems, fallow and tea had higher C and N levels. Tea. Meru oak
forest, cypress and, pine forest ranked among the best in abundance, richness and
diversity. Fallow had high mites abundance but ranked lower in diversity due to its ,
unevenness. High acidity had a positive correlation on the abundance, family richness
and diversity of soil mites. Cypress forest, pine, and tea had higher acidity than other
LUT and still ranked among the best in abundance, richness and diversity. Agroecosystems
comprising of maize-based system, coffee, and horticulture had less acidic
soils and showed low abundance, richness and diversity of soil mites. The agroecosystem
comprising of maize-based, coffee, and horticulture yielded lower mites abundance,
richness, and diversity while the forest ecosystem and tea ranked among the best. LVT
was found to significantly affect the abundance, richness and diversity of soil mites
(P:S0.05). Each LUT had unique mites community structure. A total or 37 and 29 families
were recovered at Taita and Embu, respectively. The oribatida mites had 16 and 20
families in Embu and Taita, respectively followed by mesostigrnata with 9 and 10
families in Embu and Taita, respectively. Embu had 4 prostigmata families with Taita
having 7. The families that ranked highest in abundance across the LUT at the two sites
were Scheloribatidae, Oppidae (Oribatida) and Rhodacaridae (mesostigmata).
The dry and wet seasons had a significant effect on family richness and diversity of soil
mites at Embu while at Taita where sampling was on two wet seasons there was no
significant effect (PSO.OS). Seasons were found to affect the soil mites with the wet
season in Embu supporting higher mites richness and diversity than the dry season as
mites migrate vertically in relation to moisture gradient.
LUT and soil chemical parameters (C, N and pH) were demonstrated to affect abundance,
richness and diversity of soil mites. In relation to the important role mites play in
decomposition and nutrient cycling, conservation of the forested ecosystems and
adoption of agro-ecosystern designs (planting of perennial crops such as tea, napier and
fallowing) is important to conserve soil mites. | en |
