Ian C. Trueman

Relationships between soil characteristics and species richness in two botanically heterogeneous created meadows in the urban English West Midlands

Understanding the relationship between soil fertility and species richness in mesotrophic meadows is important for the conservation of species-rich grassland and particularly for habitat creation. This relationship was investigated in surveys of two heterogeneous created meadows. Redundancy analyses of species abundance data and related soil parameters (extractable phosphorus and extractable potassium, mineral nitrogen, pH, loss-on-ignition, texture and moisture) indicated that phosphorus and potassium concentrations separately accounted for most variation in species composition at the different meadows. Contrary to expectation, low potassium was associated with low diversity, although low phosphorus was associated with high diversity. The concentration ranges in the optimal stands most closely related to species richness are: <7 mg extractable P 100 g−1 (Truogs extraction) and 10–30 mg extractable K 100 g−1. These ranges are expected to be useful in evaluating soil nutrient status prior to habitat creation.

A comparison of the effects of four arable crops on the fertility depletion of a sandy silt loam destined for grassland habitat creation

Species-rich grassland habitat creation depends on low soil fertility for success. However, past eutrophication of potential sites frequently requires fertility depletion before the establishment of species-rich swards. Therefore, this experiment investigated the effectiveness of four arable crops in depleting the fertility of a sandy silt loam. Barley, potatoes, maize and tobacco were grown for two full seasons without fertiliser and the changes in several soil parameters (total nitrogen, phosphorus and potassium; nitrate; extractable P and K; soil pH and loss-on-ignition) were compared. Bioassays using Lolium perenne as a test species were performed. There were major changes in available nutrients, with significant differences between treatments after two years. Barley depleted soil concentrations of nitrate, extractable phosphorus and bioassay yields significantly more than other treatments. Therefore, we believe that cereal growth over two years or more provides the best crop treatment for fertility depletion prior to habitat creation. Although no continuing decline in total nutrient pools was achieved, it is postulated that the removal of available soil nutrients immediately prior to seeding allows the establishment of a species-rich sward, which can be maintained subsequently by appropriate management.

Morphodynamics of the Morfa Dyffryn coastal dunes, mid-Wales: photographic survey 1988–2007

In this 20-year case study on the Morfa Dyffryn dunes, Gwynedd, mid-Wales (National Grid Reference: SH563240), straightforward and inexpensive photography, from fixed points and angles, proved useful for monitoring the evolution and migration of dynamic dune landforms. The mobile foredunes are particularly dynamic with cyclical morphological development paralleling an overall landward recession, evident by exposure of a World War II bunker in 1995. A cyclical trend is documented through photosets. The dune meadow has undergone cyclical patterns of sand encroachment, followed by stabilization by vegetation, while the fixed hind dunes remain stable. A general relationship between foredune morphology and erosion/accretion processes has been established, offering the prospect of predicting future dune morphological changes. Keywords: coastal dunes, photographic survey, erosion/accretion processes, pedogenic development, coastal change.

The use of the axiophyte species concept to describe the ecological network of the Birmingham and Black Country of the UK West Midlands

Abstract The UK conurbation of Birmingham and the Black Country has recently been surveyed for a new Flora, on the basis of a 1 km square grid. The present paper uses the data to describe the ecological network of the conurbation. The total number of taxa per 1 km squares is shown to be moderately but significantly correlated, and the number of native taxa more strongly correlated, with the area of the previously-established network of protected sites. Nevertheless coincidence maps of total numbers or numbers of native species per 1 km square give only poor representations of the ecological network compared with maps of protected sites. Axiophytes are defined as plant species 90% restricted to conservation habitats and recorded in fewer than 25% of 2km × 2km squares in a county. Applying the concept to 1 km squares in Birmingham and the Black Country creates a list of 256 axiophytes. Numbers of axiophytes are shown to be more strongly correlated with areas of protected sites than total taxa or native taxa and a coincidence map of the axiophytes is found to provide a useful quantitative assessment of the ecological network. Maps of axiophytes are used to divide the network into core and linking areas and their use in consolidating and improving the botanical ecological network is explored.