Vegetation Analysis

Vegetation Analysis Case 1

Problem

Concern that limestone dust from an active Mendips quarry might affect bryophytes in an adjacent woodland SAC.

Solution

Survey of the distribution and condition of mosses within the wood was undertaken by AEcol Associate and bryophyte specialist Nick Hodgetts.

The survey concluded that the overall site condition was in fact good, and whilst dust was causing damage to some mosses growing very close to the edge of the wood, this was offset by greater abundance of a number of species, the limestone dust enabling them to colonise trees with acidic bark from which they would otherwise be absent.

In-house wind-data analysis by the AEcol team concluded that historic loss of calcifuge species was probably attributable to dust from a number of quarries in the surrounding area, some of which were no longer operational. In addition, losses of common species from a watercourse could be attributable to an approved increase in the consented discharge from the quarry rather than to dust.

The analysis proved that none of the effects were significant and these findings were subsequently accepted by Natural England.

Vegetation Analysis Case 2

Problem

Following the submission of a planning application for a basalt quarry, an objection was raised by the Northern Ireland Environment Agency which required additional detailed botanical appraisal of the habitats there present, including the nationally rare species whorled caraway Carum verticillatum and the plant community.

Solution

In order that those parts of the site that were not of high importance might be considered for quarrying, AEcol designed and conducted detailed botanical survey to map the location and extent of whorled caraway and all vegetation communities within the site. Vegetation was recorded from 68 quadrats and data were analysed using TWINSPAN and MAVIS software to identify and map the plant communities present. Soil moisture was also sampled.

This enabled the production of a plan clearly defining areas of low and high value, and suggested a scheme of management, under which the higher value community of fen meadow might be enhanced, so compensating for any negative effects from the loss of lower value areas.