Diseño de un sistema de gestión automatizada en museo

T w o different field sites were selected, in order to compare the behaviour of the experimental plants m m eadow and woodland grassland habitats. T h e m eadow site selected was Martin's M eadows - a group of ancient species-rich hay m eadows. The woodland field site was the Bradfield W oods - an ancient coppice woodland with species-rich rides and glades. Both sites are Sites of Special Scientific Interest (SSSI) and both are managed as nature reserves by the Suffolk Wildlife Trust (SW T). They were selected because each represents an excellent example of its respective habitat type, and because SW T was happy to allow this research to be earned out on its reserves. Both sites are described below and their locations are show n in figure 1.1.

Nortblk. North S ea Suffolk (Cambridgeshire Bur\- St.

H dm und s Bradfield W oods

Martin’s M eadows

Ipswich

Essex

Figure 1.1 T he location of M artin’s M eadows and the Bradfield W oods.

1.5.1 Martin's M eadows

Martin's M eadows (grid reference T M 228572) have an area of 3.9ha and comprise

three small m eadows, two of which are species-rich Centaurea mgra - Cynosurus cnstatus

(M G 5) meadows (See Chapter 2 for an analysis of the vegetation ). T he soil is a chalky boulder clay of pH 6-7 and the two species-rich meadows contain the full range of species typical of boulder clay m eadows.

Introduction

T he finest of the three m eadows is First Church M eadow (see figure 1.2). It is a Nature Conservation Review (Ratcliffe, 1977) site, and as such is one of the best M G 5

m eadows in Britain. T he second species-rich m eadow (subsequently referred to as Martin's M eadow) contains m ost o f the species present in First Church M eadow , but the sward has a lower density of many of the dicotyledonous species. Having said this, it

IS still a very fine example of a chalky boulder clay meadow. T he large middle m eadow is

rather species-poor, as it was used as a chicken run in the past and has suffered greatly from nutrient enrichment.

P on d Road First Church M eadow I ledges C I r c h a r d • .WM2 Martin’s M eadow .\t.VV3 100 m

Figure 1.2 A map o f M artin’s M eadow s, showing the locations of the three

As far as is known, First Church Meadow and M artin's Meadow have never been ploughed, drained, reseeded or fertilized. The SW T established a management agreement over the meadows in 1971 to ensure continued sympathetic management. Hay has always been cut in July, with sporadic aftermath grazing and sometimes a second autumn hay-cut. T he T rust has used its own sheep for autum n grazing in 1989, 1990 and on First Church Meadow in 1992. The meadows were not cut in 1991. Although there is no recorded history, the presence of poisonous Colchicum autumnale leaves make it unlikely that the meadows were ever grazed in the summer.

Fieldwork was carried out in Martin's Meadow, as First Church Meadow was

considered too valuable to suffer experimental management. However, the vegetation of First Church Meadow was studied and some seeds were collected from this meadow. Three sites within Martin's Meadow were used for experimental work. These are shown in figure 1.2. All were in broadly similar vegetation, although site 2 was in an area with a higher proportion of Plantago lanceolata. These sites are subsequently referred to as M M l, MM2 and M M 3, respectively. First Church M eadow is usually referred to as FC M in the following text.

1.5.2 Bradfield Woods

The Bradfield Woods (grid reference T L 925577) have an area of 65ha. They are almost entirely of ancient origin and are managed largely as coppice-with-standards, having been managed as such continuously since at least 1252. This continuity of management, together with their great complexity of soil types and drainage, has produced a tremendous diversity of species, with over 370 plant species recorded. The woods lie on an undulating plateau of chalky boulder clay. This is overlain in places by up to 1.5m of sand and 0.5m of loess. These three elements are mixed in varying proportions to produce an exceptionally wide range of soil texture and acidity. The pH varies from 3.0 to 7.3 and every woodland com partm ent has both acid and calcareous areas. T he woods are also a classic site for sand lenses. These have the most acid soils and are marked by bracken glades. As in most ancient woodlands, the soils appear to be somewhat deficient in phosphates.

T he coppice compartments (known as fells) are managed on a ten to twenty year rotation. They are divided by rides, which are the chief m odem representatives of woodland grassland. The rides date mainly from the 17th and 18th centuries but can be regarded as ancient grassland (Bradfield Woods management plan). In addition to the rides there were two deer park launds (clearings) in the Monk's Park section of the woods, dating from medieval times. One of these - Hewitt's Meadow, with an area of lh a - was later managed as a meadow and as arable but became wooded, through

Introduction

neglect, in about 1890. In 1984, however, the trees were felled and the area was restored to grassland. The other laund - Roots Meadow - also became wooded in the late 19th century, but unlike Hewitt's Meadow, it has not been restored to grassland. The rides are managed to provide a transition from short turf to woodland. T he middle strip, 2m wide, is cut mechanically twice a year to give a short turf. T he sides of the rides are cut every two years (one side of each ride each year) and the edges of some of the fells are coppiced on a short rotation to enhance the transition to woodland. Dense growths of bramble and rose in the ride edges are usually preserved. Hewitt's Meadow is scythed annually.

Within Bradfield Woods, three areas were selected as field sites. These differed from each other to varying extents and were designed to test the responses of the

experimental plants in a wide range of woodland grassland types. The three sites are shown on the map in figure 1.3, and they are described below:

• An area of recently-cut coppice in the Middle Fell, close to the Bluebell Track. The site was largely unshaded, except for two or three medium-sized silver birch trees. T he soil was dry and sandy and the vegetation was of sparse grasses and bramble. This site is referred to as the Bradfield Woods Coppice, or BWC.

• A triangular area of rank grass and herbage at the intersection of Broad Ride and Felsham Hall Ride. This area was surrounded by some moderate-sized trees but was open to the sky immediately overhead. The soil was moist and the vegetation was quite coarse, growing to over Im in height in summer. This site is referred to as the Bradfield Woods Triangle, or BWT.

• A 2m wide grassy strip along the south-eastern side of Cargate Ride, shaded on either side by the trees of the adjacent coppice fells, but open to the sky immediately above the ride. The soil was moist and the vegetation was quite lush. This site is referred to as the Bradfield Woods Ride, or BWR.

__ Road

\\ Coppice plot

Coppice compartment

Ride Triangle plot

I’ond

H ew itt’s

M eadow _{500 m}

Figure 1.3 A map of the Bradfield W oods showing the location of the three

experimental sites.

Introduction

1.6

Selection o f the experim ental plant species

T he suite of plant species selected for experimental investigation had to fulfil a num ber of criteria.

• They had to include species which were found in both the meadow and the woodland field sites, and species which were restricted to each of these sites.

• They had to represent a range of taxonomic groups, growth forms and life histories.

• They had to be relatively abundant at the sites from which they were taken, as around 60 plants of each species would be used in the experiments. Whilst it might have been of greater potential conservation interest to have worked on rarer meadow and woodland species, this was unacceptable, given the scale of the experiments.

In the end, 13 species were selected. These were as follows: Agrostis capillaris Alopecurus pratensis Anthoxanthum odoraturn Deschampsia cespitosa Holcus lanatus Centaurea nigra Cerastium holosteoides Mentha x verticillata Plantago lanceolata Primula veris Prunella vulgaris Ranunculus acris Rumex acetosa

Details of the sites from which the experimental plants originated for each particular experiment are given in the “M ethods” sections of the subsequent chapters.

C hapter 2

V egetation com position