Wetland habitats, their resource potential and exploitation: a case study from the Humber wetlands

The notion that wetlands are among the most productive environments in the world is widely quoted, but its relationship with the exploitation of wetland ecosystems during the prehistoric and early historic period has been the subject of few investigations. The current paper discusses the primary production of different wetland habitats and its relationship to the resource potential of these habitats and their actual exploitation, using recent results from the Humber Wetlands Survey. It is argued that during the early Holocene, wetland landscapes were central to the subsistence economy and that a clear association exists between the primary productivity of wetlands and the intensity of exploitation. With the introduction of agriculture, however, wetland habitats become increasingly peripheral to the economy

Equilibrium Distribution Studies of Dysprosium Nitrate-Erbium Nitrate- Nitric Acid-Tributyl Phosphate Systems

Separate equilibrium data were obtained for the distribution of Dy(NO/ sub 3/)/sub 3/- HNO/sub 3/, Er(NO/sub 3/)/sub 3/- HNO/sub 3/, and Dy(NO/sub 3/)< i3>iEr(NO/sub 3/)/sub 3/-HNO/sub 3/ systems between water and tributyl phosphate. Equilibrium data for the Dy(NO/sub 3/)/sub 3/- HNO/sub 3/ and Er(NO/sub 3/)/sub 3/ -HNO/sub 3/ systems were correlated in such a manner that the total distribution of solutes and nitric acid could be found for the Dy(NO/sub 3/)/sub 3/- Er(NO/sub 3/)/sub 3/- HNO/sub 3/ system. The separation factor between Dy(NO/sub 3/)/sub 3/ and Er(NO/sub 3/)/sub 3/ is shown as a function of the total molality of the aqueous phase. A method is presented for predicting the concentrations of Dy(NO/ sub 3/)/sub 3/, Er(NO/sub 3/)/sub 3/, and HNO/sub 3/ in an organic phase of tributyl phosphate from their concentrations in the aqueous phase at equilibrium, and the results of the method are compared with experimental data. (D.L.C.

Yarborough Quarry

No description supplie

Can we characterise ‘openness’ in the Holocene palaeoenvironmental record? Modern analogue studies of insect faunas and pollen spectra from Dunham Massey deer park and Epping Forest, England

This paper examines the degree to which tree-associated Coleoptera (beetles) and pollen could be used to predict the degree of ‘openness’ in woodland. The results from two modern insect and pollen analogue studies from ponds at Dunham Massey, Cheshire and Epping Forest, Greater London are presented. We explore the reliability of modern pollen rain and sub-fossil beetle assemblages to represent varying degrees of canopy cover for up to 1000 m from a sampling site. Modern woodland canopy structure around the study sites has been assessed using GIS-based mapping at increasing radial distances as an independent check on the modern insect and pollen data sets. These preliminary results suggest that it is possible to use tree-associated Coleoptera to assess the degree of local vegetation openness. In addition, it appears that insect remains may indicate the relative intensity of land use by grazing animals. Our results also suggest most insects are collected from within a 100—200 m radius of the sampling site. The pollen results suggest that local vegetation and density of woodland in the immediate area of the sampling site can have a strong role in determining the pollen signal