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Woodland creation and ecological networks: Quantifying the relative importance of different attributes on biodiversity (Phase 1) - LM0313

Description
The concept of landscape-scale “ecological networks” has emerged from efforts to reduce, and ultimately reverse, widespread habitat loss and fragmentation; the implementation of these is now a high priority in current conservation policy. Ecological networks are typically conceptualised as a suite of core high quality habitat patches connected by buffer zones, corridors and smaller adjacent patches “stepping stones” that allow species or their propagules to move between them (Lawton et al. 2010).

However, while the concept of ecological networks is based on sound scientific principles, designing networks in practice is complex. A range of different attributes - for example, how big a patch of habitat is, how far it is from other patches, and how long it has been established - will affect how well sites in a network support populations of different species. These attributes will also interact with each other and so it is essential to consider the full set of attributes together. This is something that very few past studies appear to have done (Humphrey et al. 2013), and is a major weakness in our current knowledge.

The long programme of woodland creation, including those created more recently under Woodland Grant and Agri-environment Schemes, within the UK has inadvertently created a series of historical test landscapes of differing characteristics. We have used these to generate a suite of woodland “typologies” which represent different components of ecological networks and assess their relative importance in maintaining biodiversity within woodlands. The recent availability of digitised historic maps (e.g. Ordnance Survey, Dudley Stamp Land Utilisation maps) going back to 1840 provide the opportunity to reconstruct past landscapes and assess the relative importance of age, in addition to site and landscape variables, on contemporary biodiversity.

Fieldwork was carried out in 2013 in 31 woodland sites around Stirling. These sites were chosen to encompass a range of woodland sizes, surrounding habitat, degree of isolation, and ages. Species surveyed included vascular plants, ground beetles and spiders, bats and other small mammals. The proposed next stage of the project will complete species identification from field samples (e.g. pitfall traps for invertebrates, bat recordings) to species or species group. Measures of species diversity, relative abundance, and occurrence of woodland-dependant species will be used as response variables within a Generalised Linear Model framework to explore the associations of different taxa with woodland age, character and surrounding landscape. Specific questions to address include:
1. What is the relative importance of site (e.g. area, quality), vs. landscape-scale features (e.g. surrounding habitat, isolation, matrix permeability) in determining species diversity and population abundance of key taxa in lowland agricultural woodlands;
2. How do important predictors of species diversity and abundance identified in (1) interact with the effects of woodland age?;
3. Which conservation actions, particularly through agri-environment schemes, would be most effective for different species, given different starting points of woodland extent/configuration, and how should these actions be targeted at holding and landscape level?

The results will provide specific conclusions for conservation practitioners about design and management of ecological networks for woodland species.




Objective
The overall aim of this project is to address the following questions:
1. What is the relative importance of site (e.g. area, quality), vs. landscape-scale features (e.g. surrounding habitat, isolation, matrix permeability) in determining species diversity and population abundance of key taxa in lowland agricultural landscapes;
2. How do important predictors of species diversity and abundance identified in (1) interact with the effects of woodland age?;
3. How can we use this information to accommodate the needs of different woodland taxa (e.g. taxa with conflicting requirements)?

Specifically for this tender, we will produce the following outputs:
1. Completion of the identification for all key taxa surveyed in 2013;
2. Collection of new data on lichens for all sites surveyed in 2013;
3. A summary all the field survey data from 2013, with descriptive statistics to provide information on the numbers of species, relative abundances / activity levels across sites.
4. A report on preliminary analyses for currently available data (i.e. plant and small mammal species) and a framework for future statistical analysis of the remaining data;
5. Production of interim briefing notes using available information in the literature (outlined in Humphrey et al. 2013).

The work will be completed by the University of Stirling, with support from subcontractors and partner organisations.
Time-Scale and Cost
From: 2014

To: 2014

Cost: £47,571
Contractor / Funded Organisations
University of Stirling
Keywords
Ecology              
Woodland