Sensitivity 1 Jackknifed sample removing individual selleckchem experts (average of all jackknives presented), Sensitivity 2 PHB unweighted by expert confidence, Sensitivity 3 PHB unweighted by expert opinion For each option a habitat quality (HQ) score was calculated as: $$HQ_i = PHB_i \times ELS_i$$ (2)where ELS i is the ELS points value (and therefore farmer payment) attached to each unit of option i. This weights the quantitative metric of option quality relative to the scale of their implementation as a single hectare of habitat will typically provide a substantially greater total resource than a single metre of
habitat. How ELS points are derived is presently unclear as although EU rules state they must be based upon their costs, including income foregone, earlier and recent revisions taking into account the biodiversity benefits of options have moved away from this initial approach (Natural England 2012, 2013b). As such ELS points largely represent relative general biodiversity benefit, which is then weighted by the expert PHB scores. To give a measure of the value of each option relative to all other options with the same unit category (c), proportional habitat quality (pHQ ic ) values are then estimated as: $$pHQ_ic
= \fracHQ_ic \mathop \sum \nolimits_i = 1^C HQ_ic $$ (3)The pHQ score for option i therefore represents its benefit to pollinator habitat relative to all other options within category c. pHQi scores are therefore always between 0 and 1 and the sum of all pHQi scores for a given category of c always equal 1. Using these pHQ values, three variant analyses SGC-CBP30 manufacturer were conducted to redistribute the overall selleck screening library composition of options towards a composition which reflects the relative benefits of the options for providing good quality habitat for pollinators. Model A generates a mix of options that redistribute the absolute area of ELS options currently utilised to reflect their relative benefits to pollinator oriented habitat. It thus redistributes the composition of options based upon the total utilised area of ROCK inhibitor options within each category (i.e. the most beneficial option will take up the greatest number of units
and so on). The area of different option categories is maintained to reflect current uptake patterns and preferences. This model allows the total number of ELS points, and therefore the total area of English farmland enrolled in the scheme, to expand, however no additional area of land is taken out of production. $$U_ic = \mathop \sum \nolimits U_c \times pHQ_ic$$where U ic is the redistributed number of units of option i in category c, Uc is the total number of units (meters, hectares or trees/plots) in the category and pHQ ic is the percentage of total HQ (calculated as in Eq. 2) in each option represents within the category. As such each option is allocated a percentage of the total units of category c based upon their relative benefit to pollinator habitat.