In many mid-Atlantic forests where both native and non-native earthworms exist, it is the nonnative species that are the dominant component of the soil macrofauna. Few earthworm ecology studies, however, focus attention on these forest systems in order to determine the relative ecological roles and potential interactions of the native and non-native earthworms. In a series of field samplings and experimental manipulations we collected data on the effects of earthworms on below-and aboveground ecosystem processes. Earthworm abundance and the ecological processes measured were dynamic in space and time across the range of study sites. Leaf litter decay rates doubled at sites that had abundant non-native earthworms. Earthworms also altered the abundance of soil fungi, the activity of extracellular enzymes, soil respiration, and the growth of tree seedlings but the effects varied among sites depending on differences in land-use history and forest age. Red oak seedling growth was less at sites that had abundant earthworms but tulip poplar and red maple seedlings grew equally well with and without abundant earthworms. These preliminary results suggest that non-native earthworms have significant ecosystem effects, even in forests where native earthworms still occur. Land use history, however, plays an important role in determining what those effects will be, and these effects are likely to be dynamic, depending on the abundance of non-native earthworms.
Acer truncatum is an important ornamental, edible,
and medicinal plant resource in China. Previous phytochemical research
has focused on the leaf (AL) due to its long history as a tea for
health. Other parts such as the branch (ABr), bark (ABa), fruit (AF),
and root (AR) have drawn little attention regarding their metabolites
and bioactivities. The strategy of an in-house chemical library combined
with Progenesis QI informatics platform was applied to characterize
the metabolites. A total of 98 compounds were characterized or tentatively
identified, including 63 compounds reported from this species for
the first time. Principal component analysis showed the close clustering
of ABr, ABa, and AR, indicating that they share similar chemical components,
while AL and AF clustered more distantly. By multiple orthogonal partial
least-squares discriminant analyses (OPLS-DA), 52 compounds were identified
as potential marker compounds differentiating these different plant
parts. The variable influence on projection score from OPLS-DA revealed
that catechin, procyanidins B2 or B3, and procyanidins C1 or C2 are
the significant metabolites in ABa extracts, which likely contribute
to its antioxidant and cytotoxic activities.
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