Long term ecological change in British woodland (1971-2001)
A re-survey and analysis of change based on the 103 sites in the Nature Conservancy 'Bunce 1971' woodland survey
K. J. Kirby, S. M. Smart, H. I. J. Black, R. G. H. Bunce, P. M. Corney and R. J. Smithers
Long term ecological change in British woodland (1971-2001)
A re-survey and analysis of change based on the 103 sites in the Nature Conservancy 'Bunce 1971' woodland survey
K. J. Kirby, S. M. Smart, H. I. J. Black, R. G. H. Bunce, P. M. Corney and R. J. Smithers
Tartalom:
Preface
Acknowledgements
Executive Summary
1. Introduction
1.1. Background to the 1971-2001 survey project
1.2. Derivation of the original 103 woods - the 'Steele' survey
2. Methods
2.1. Field survey
2.2. Soil sample processing and analyses
2.3. Validation of soil analytical methods
2.4. Vegetation and habitat data processing
2.5. Dealing with potential bias (systematic errors)
2.6. How representative is the sample?
2.7. Approaches to vegetation analysis
2.7.1. Grouping of species by indicator values
2.7.2. Mixed modelling approach to variable analysis
2.7.3. Overview of the variables used in the analysis
2.8. Relationship between signal detection and attribution
2.9. Exploring drivers of change via direct hypothesis testing
3. Results
3.1. Introduction to the results
3.2. Lost plots and changing land-use between 1971 and 2002 survey
3.3. Vegetation types
3.4. Summary of changes in plot type
4. Variation within the survey sites in 1971
5. Comparison of the soil records for 1971 and 2001
5.1. Soil pH
5.2. Change in soil organic matter (SOM)
5.3. Summary of GB level soil changes
6. Tree and shrub comparisons 1971-2001 and management changes at the GB level
6.1. Overall tree and shrub composition
6.2. Diameter distribution of trees and shrubs
6.2.1. Diameter distribution and abundance of dead stems
6.3. Change in basal area of trees and shrubs between 1971 and 2001
6.4. Regeneration
6.4.1. Site level sapling regeneration
6.4.2. Plot level sapling regeneration
6.4.3. The abundance of tree and shrub seedlings
6.5. Changes in indicators of woodland disturbance
6.5.1. Open habitats
6.5.2. Site level signs of recent management
6.5.3. Woodland activities noted in the surveyors' reports
6.5.4. Grazing signs
6.6. Summary of tree and shrub/management changes
7. Ground flora changes
7.1. Changes in ground layer species richness (excluding bryophytes and lichens)
7.1.1. Explaining change in species richness
7.2. Change in frequency of indivudial species
7.2.1. Change in frequency of Woodland Specialist species
7.3. Change in cover of individual plant species
7.4. Changes in species composition between 1971 and 2002 - Multivariate analysis
7.5. Changes in the distribution of different Ellenberg scores
7.5.1. Ellenberg fertility (N) and pH (R) scores
7.5.2. Ellenberg light scores
7.5.3. Ellenberg wetness scores
7.5.4. Interactions between Ellenberg Light, Fertility and Reaction Scores
7.6. Changes in UCPE Plant Strategy types
7.7. Climate variables and changes in ground flora species composition
7.7.1. Effect of mean Jan-March temperature change
7.8. Analysis of change in total ground flora cover
7.9. Summary of ground flora results
Summary of key results
8.1. Summary of changes
8.2. Summary of changes by numbers of sites
8.3. Summary of results in relation to potential drivers of change
8.4. How successfully has the linking of responses and variables been?
Discussion
9.1. Strengths and weakness of the study
9.2. Relating possible drivers of change via landscape, woodland and stand level processes
9.3. Climate change
9.4. Changing nutrient inputs and outputs
9.4.1. Soil pH changes
9.4.2. Nitrogen enrichment
9.4.3. Relations between nitrogen, pH and soil organic matter
9.4.4. Increased inputs or reduced outputs?
9.5. Grazing in British woodland
9.6. Stand growth and succession in the woods
9.6.1. Why have woodland specialists declined so much?
9.7. Further research questions
10. Using the results to explore changes in the 'condition' of broadleaved woodland 1971-2001
10.1. Woodland extent
10.2. Structure and natural processes
10.3. Regeneration potential
10.4. Tree and shrub composition
10.5. Quality indicators
10.6. Overall assessment
11. Future trends?
11.1. Climate change
11.2. Nutrient status
11.3. Management changes
11.4. Endnote
References
Címszavazva - GE
