This chapter describes the valuable range of features which urban green spaces contain. Before any decisions are made about practical work on sites, it’s important to find out what is there already. Site surveys should include the flora and fauna, soil and exposures of rock. The industrial or land use history of the site is also important, not only for its part in local history, but for understanding the way in which plant and animal communities have developed on the site.
In the last decade, the interest in urban wildlife has grown enormously, and many towns and cities have active urban wildlife groups who have surveyed the green spaces in their local area, and compiled species lists for some sites. Some county wildlife trusts and the statutory nature conservation bodies have staff with particular responsibilities for urban areas. Local authorities or museums may be responsible for biological databases. There is already a fund of knowledge about many areas, and the first move when considering surveying a site should always be to check for existing information, through the above organisations. Most areas have standard methods for surveying and recording, which should be followed, so further monitoring and comparisons with other sites can be usefully carried out.
Site surveys can be done at two levels. The first level is a general survey of the site, recording a general site description, natural history observations and the site history. The site is then divided into parcels of distinct habitat or management type, and each parcel is checked for a range of characteristics, including bare ground, vegetation types, water, substrate, drainage and land use. A sketch map is made to show the boundaries, adjacent land use, access and other features. This initial survey indicates the areas of natural history interest which need further surveying.
The second level of survey is to record species of flora and fauna present, concentrating on those groups for which the site appears to be valuable. Quantitative data, which indicates the amount or frequency of each particular species, is helpful. Flora, birds and butterflies are the easiest to record, and it should not be difficult to find someone able to do this. More specialist knowledge and skills are required for recording mammals, reptiles, amphibians, fish, invertebrates, fungi, ferns, mosses and lichens.
This knowledge provides a basis for informed discussion about the site, and gives a base line for future monitoring. Such a survey should be objective and accurate, but the value which different people place on the various species, and how any management may affect them, may be subject to further discussion between different interest groups. The site also needs to be assessed in relation to other sites in the area. If it is uncommon in the area, this may increase its value. On the other hand, sites that are small and isolated from other similar sites may not be able to support viable populations. See the section on size and isolation.
