Diazinon (O,O-diethyl O-[2-isopropyl-6-methyl-4pyrimidinyl] phosphothiate) is an organophosphate pesticide with widespread use on a variety of agricultural crops, such as fruit trees, corn, and tobacco (Burkepile et al., 2000). Approximately 6 million kg of diazinon are applied annually in the United States and, as a result, are a potential contributer to nonpoint source contamination of aquati...

BACKGROUND Xeric forests dominated by two tree species, Scutia buxifolia (Rhamnaceae) and Celtis tala (Ulmacea), are temperate, semi-deciduous wooded communities that represent the most abundant woodlands on the eastern plains of Buenos Aires Province, Argentina. The district of Magdalena has one of the most well-preserved native-forest areas, with an environmental heterogeneity that gives rise...

Ants are known to function as reliable biological indicators for habitat impact assessment. They play a wide range of ecological roles depending on their feeding and nesting habits. By clustering ants in guilds, it is possible both to assess how agriculture and forest fragmentation can disturb ant communities and to predict the ecological impacts due to losses of a specific guild. This study ai...

Vermicomposting of the pre-composted leaf litter of acacia (Acacia auriculiformis) was studied in reactors of identical volume but with surface area: height ratios varying from 4 to 250. In separate sets of experiments with these reactors, epigeic earthworm species Eudrilus eugeniae and anecic earthworm species Lampito mauritii were employed at densities of 75 and 150 adult animals per litre of...

Nonnative, invasive shrubs can affect human disease risk through direct and indirect effects on vector populations. Multiflora rose (Rosa multiflora) is a common invader within eastern deciduous forests where tick-borne disease (e.g. Lyme disease) rates are high. We tested whether R. multiflora invasion affects blacklegged tick (Ixodes scapularis) abundance, and at what scale. We sampled host-s...

We assessed the role of ecological and evolutionary processes in driving variation in leaf and litter traits related to nitrogen (N) use among tropical dry forest trees in old-growth and secondary stands in western Mexico. Our expectation was that legumes (Fabaceae), a dominant component of the regional flora, would have consistently high leaf N and therefore structure phylogenetic variation in...

Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We specifically asked whether the processes structuring leaf-litter anuran assemblages in fragmented fo...

Urbanization can alter the organization of ant communities and affect populations of urban pest ants. In this study, we sampled ant communities in urban and suburban yards to understand the habitat factors that shape these communities and influence the abundance of a common pest species, Tapinoma sessile (Say). We used pitfall traps to sample ant communities and a combination of pitfall traps ...

The main objective of this thesis was to examine the effects of climate change and simulated herbivory (artificial foliage damage) on growth responses and leaf characteristics (chemical and morphological structure and consequent palatability) of silver birch (Betula pendula) seedlings. In order to achieve this target, seedlings were grown in climate controlled closed-top chambers under ambient ...

While techniques for sampling pond-breeding amphibians are relatively well-established, comparable methods for stream amphibians are still being developed. Uncertainty about sampling techniques is particularly acute for approaches that involve multiple observers. I evaluated three techniques for sampling stream salamanders with multiple observers—time-constrained surveys, leaf-litter bags, and ...