Birds of the Shiant Islands,Outer Hebrides

This report of two Cambridge University expeditions to the Shiant Islands draws together their own and previous records concerning the bird-life of the islands, and presents the results of attempts to count the sea-bird populations.     

An annotated flora of the Monach Isles national nature reserve,Outer Hebrides

Summary

The term machair is commonly applied to the landform/vegetation systems of many dune pasture areas of parts of the Highlands and Islands of Scotland. Definition of such areas appears to rest on locational, morphological, vegetational and soil criteria. Closer examination suggests that the main diagnostic feature is the soil parent material, shell-rich blown sand, which gives rise to high calcium carbonate and pH conditions. Secondary criteria include the morphological maturity of the machair surface, the absence of depositional processes, specific plant associations (notably the elimination of long dune grasses) and a history of grazing and, possibly, cultivation. Machair areas must also be set in a cool, moist maritime climatic regime.     

Machair zonation of the Monach Isles,N.N.R., Outer Hebrides

Summary

The vegetation of the Monach Islands is described by means of a grid of 336 1 m quadrats. Using the error sum of squares statistic these quadrats are grouped into seven communities and a residue: a brief outline and a frequency table of each is presented. These communities are seen to result in a zonation away from the sea which is related to soil differences, particularly an increase in organic matter; biotic differences, including rabbit and sheep grazing; and man's past cultivation practises.     

A mangrove community in the New Hebrides, south-west Pacific

A general survey of the mangal at Port Stanley, Malekula, New Hebrides, the most extensive mangal in the archipelago, was conducted over an 11-day period in September/October 1971. Seventeen species of true mangrove tree and mangrove associates were recorded. As is characteristic of mangal, this flora was distributed in a zonal pattern, four zones being recognized. Certain anomalies in zonation were attributed to a recent episode of crustal uplift. The aquatic component of the fauna was dominated by molluscs (26 species) and Crustacea (20 species). The terrestrial vertebrate fauna consisted of 4 species of reptiles, 21 birds and 5 mammals.
The mangrove community at Port Stanley is an integral part of that of the Indo-West Pacific region. However it is much restricted in number of species, and reasons for this are suggested: distance from Malesia, lack of fresh water, and shallow soils with little silt deposition. Faunal impoverishment is clearly associated with floral impoverishment.