Biodiversity indicators for UK habitats: a process for determining species-weightings. Ed Rowe

Transcription

1 Biodiversity indicators for UK habitats: a process for determining species-weightings Ed Rowe

2 Outline Progress with UK model chain What can our models predict? Why weight species? Alternative species weightings A process for deciding

3 UK model chain progress MADOC = VSD & N14C & ~DyDOC (Finally) submitted to Environmental Pollution Predicts C, N, ph, Dissolved Organic Carbon (DOC) MultiMOVE R package submitted to Methods in Ecol & Evol Extending to coastal species Biodiversity metric DEFRA (UK govt) call issued 20 th March to Define a metric to inform the UK s response to the CCE Call for Data Project runs May-Aug Predicted DOC g m -2 y Subsequent DEFRA call planned (~September) to meet Call for Data Measured DOC g m -2 y -1

4 What can current models predict? Scenarios for different drivers Biogeochemistry model Floristics model e.g. MultiMOVE, PROPS, VEG e.g. SMART, MAGIC, MADOC, FORSAFE Habitat suitability for a set of plant and lichen species Habitat quality, damage & recovery

5 What is habitat suitability? e.g. MultiMOVE trained on prevalence (occurrence) data but occurrence is affected by dispersal & extinction rates so predicts habitat suitability, not occurrence

6 Does habitat suitability predict abundance? e.g. Agrostis stolonifera Observed cover (all CS2007 soil plots) vs. MultiMOVE-predicted habitat-suitability Not very well, although high cover values not found at low habitat suitability This implies that indices that include evenness cannot be well-predicted

7 Canopy Height Class Mean change index (+/- s.e) Typical height cm Which species are affected by nitrogen? a) b) 'UK' Ellenberg N value d c 3.4 bc 3.2 ab 3.0 a Threatened Rare Uncommon Decreasing Increasing Conservation status c) y = 18.4e 0.25x R² = Ellenberg N score a) Preston et al 2002 New Atlas British & Irish Flora b) JG Hodgson, K Thompson et al. (unpublished) c) derived from Hill et al PlantAtt

8 Nitrogen affects particular species e.g. calcareous grassland Critical load (revised 2011) = N deposition rate % of UK habitat Species inhibited (> 20% decline in Species strongly inhibited (> 50% kg ha -1 y prevalence) prevalence decline) none none Allium vineale Geranium columbinum Daucus carota above species, plus Carlina vulgaris above species, plus Echium vulgare Rosa micrantha Cynoglossum officinale Cladonia foliacea Melica nutans above species, plus Campanula glomerata Spiranthes spiralis Bromopsis erecta Centaurea scabiosa above species, plus Daucus carota Ononis repens Carex spicata above species, plus Allium vineale Geranium columbinum above species, plus Carlina vulgaris Echium vulgare Rosa micrantha Cynoglossum officinale Cladonia foliacea Melica nutans above species above species, plus Campanula glomerata Emmett et al JNCC report #449

9 Why weight species? Habitat suitability for plant species can be predicted objectively Which species are considered desirable and undesirable is subjective Defining desirable species as the N-sensitive ones is circular Deciding on preferences needs to be done in relation to existing biodiversity targets and legislation

10 Why not use established biodiversity indices? Some habitats are characterised by low Species Richness (e.g. of vascular plants in heathland) Indices that include evenness (Shannon-Weaver, Simpson, etc.) are also poorly related to criteria used in assessing habitat condition Ecosystem services provision is: a) not operationally established b) likely to be maximal for monocultures, unless gamed Legislation (and conservation science) tends to favour particular species

11 Summarising effects on species HabitatQuality a UK species? b Have model? 0 1 c Relevant for Habitat? abcde d Biodiversity value of this species e Habitat suitability for this species Possible criteria: a) equal weighting for all relevant species (c.f. Czekanowski distance from target community) b) indicator species for the habitat (key, structural, distinctive, etc.; negative values for negative indicators?) c) scarcity / decline (c.f. Red List criteria) 3000

12 Example using indicator species as defined for Common Standards Monitoring under the EU Habitats Directive e.g. for English blanket bog (Moor House NNR) under CLE scenario Positive CSM indicator species Negative CSM indicator species Mean Habitat Suitability for positive CSM species minus mean for negative CSM species Probability of Occurrence / Pmax Year Probability of Occurrence / Pmax Year Habitat Quality Year Rowe et al CCE Status Report

13 Dune grassland positive indicators CSM weighting n UK hectads Scarcity weighting Geranium molle Viola tricolor Astragulus danicus Photos (c) JR Crellin under Creative Commons licence

14 A process for determining weightings Option A Identify habitat specialists Explain N pollution threat Engage specialists in process Brainstorm options Get sidetracked into discussions of ecosystem services Get sidetracked into discussions of habitat structure and function Run out of time Decide on a metric

15 A process for determining weightings Option B c.f. Bowers & Boutin 2008 Ecological Indicators 8: ; Landi & Chiarucci 2010 Systematics and Biodiversity 8: Identify habitat specialists Obtain ~20 relevés from each habitat, covering a range of quality Develop alternative quantitative metrics Ask specialists to rank relevés Rank relevés using alternative metrics Assess which metric correlates best with specialists rankings Choose this one

16 Conclusions Jobs tend to get done at the last possible moment We have models that relate N (and S) deposition trends (and climate) to habitat suitability for a subset of species Getting disparate actors to agree on an operationalised indicator, based on uncertain information, may require a structured survey approach The UK approach will be clarified in discussion with DEFRA and conservation agencies in 2013 We will meet the Call for Data on March 31 st 2014

17 Thankyou