6,726 research outputs found
Floristic variation in Sphagnum-dominated peatland communities of the Central Highlands, Victoria
The floristic composition of Sphagnum-dominated peatlands in the Central Highlands region of Victoria was surveyed (37º 25´ S; 145º 50´ E). NMDS ordination and cluster analysis divided the peatland sites into two broad groups with altitude being the most important factor separating these groups. Other important factors were aspect, slope and the amount of shade. Group 1 included subalpine sites that are similar to those found at higher altitudes further east in Victoria. Important species included Empodisma minus, Epacris paludosa, Richea continentis and Baeckea gunniana. The two species of Sphagnum present were Sphagnum cristatum and the more inundation-tolerant Sphagnum novozelandicum. Group 2 included montane peatlands with abundant Sphagnum cristatum. These sites range from broad wet heaths dominated by Richea victoriana and Carex appressa, to narrower cool temperate rainforest and riparian systems. The ‘rainforest’ peatlands are characterised by Leptospermum grandifolium, Nothofagus cunninghamii, Carex appressa and Blechnum penna-marina, and are in varying stages of post-fire succession regulated by sitespecific microclimate. The conservation status and catchment function of these peatlands are briefly discussed
Minuscule representations, invariant polynomials, and spectral covers
Given a minuscule representation of a simple Lie algebra, we find an
algebraic model for the action of a regular element and show that these models
can be glued together over the adjoint quotient, viewed as the set of all
regular conjugacy classes of the Lie algebra. There are partial results in the
case of a quasiminuscule representation, and a conjecture in the case of a
general irreducible finite-dimensional representation. The method of proof is
to relate the question to a problem concerning holomorphic principal bundles
over cuspidal cubic curves.Comment: LaTeX, 42 pages, final version, to appear in the proceedings of the
University of Missouri conference on Hilbert schemes, vector bundles and
representation theory, new material on extensions and the adjoint
representation of a simply laced Lie algebra adde
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