Assembly of plant-pollinator relationships and measurement of pollination service using seed set phytometry on regenerating lands

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1 Assembly of plant-pollinator relationships and measurement of pollination service using seed set phytometry on regenerating lands Thomas S. Woodcock Canadian Pollination Initiative, University of Guelph Pollination & Land Rehabilitation Workshop September 2012 Outline Plant and bee/syrphid assemblages in old agricultural fields Study sites Phenology of available floral resources Preliminary bee, syrphid data Pollination Service Monitoring (PSM) using seed set phytometry 1

2 Rare Charitable Research Reserve Eight research plots established in each of three former corn-soy fields Blair Flats East George Street Field Cruickston Creek Field BFE 2009 CCF 2003 GSF 2006 Rare Charitable Research Reserve Sampling plots are 5m x 5m, divided into 1m squares Plot gridded with markers Center square with flagged stake and contains pan traps (blue, yellow) 2

3 Rare Charitable Research Reserve Rare Charitable Research Reserve BFE CCF Study Sites June 2010 GSF 3

4 Rare Charitable Research Reserve Coverage and species of blooms in 1m 2 quadrat, one randomly selected for 15 min observation of flower-visitor interactions (1-2 wk interval) One person-hour qualitative sampling of flower visitors per field (1-2 wk interval) BFE Floral Resources Despite its dominance of coverage in 2010, only 16 total visits to Conyza canadensis flowers were observed n=8 n=40 4

5 BFE Floral Resources Floral coverage <10% in possible drought effects n=8 n=40 GSF Floral Resources Discontinuous resources in 2012, very dry n=8 n=40 5

6 CCF Floral Resources Greater floral diversity and coverage, drought has lesser effect? Shrubs and trees beginning to grow in 2012 n=8 n=40 Pollination Service Measurement 2011 Direct measurement of pollination service at these sites, plus abandoned gravel pit (WAY, high pollinator abundance and diversity) and old landfill (EAS, low pollinator abundance and diversity) 6

7 Diversity (H') Richness (taxa/sample) Abundance (individuals/sample) 15/10/2012 PSM 2011 Pollinator (bee, syrphid) abundance, richness, H autocorrelated, but generally... WAY, CCF highest BFE, GSF similar EAS lowest, esp. abundance ab b ab ab a BFE CCF EAS GSF WAY c bc ab ab a BFE CCF EAS GSF WAY c bc abc ab a BFE CCF EAS GSF WAY Pollination Service Measurement 2011 Three species of fall asters (Symphyotrichum) chosen... Self-incompatible Broad response range (multiple inflorescences, progressive receptivity) Filled seeds easy to count 7

8 Seeds per Inflorescence Seeds per Inflorescence Seeds per Inflorescence 15/10/2012 Pollination Service Measurement Plants bagged (control, treatment) prior to bloom in greenhouse 2. Deployed 1 week with treatment exposed 3. Re-bagged, returned to greenhouse until seed set PSM 2011 All three species were selfincompatible S. ericoides and S. cordifolium had cultural issues... bloom in greenhouse likely delayed by stray light. Corrected in S. cordifolium BFE CCF EAS GSF WAY S. ericoides BFE CCF EAS GSF WAY S. puniceum BFE CCF EAS GSF WAY Site 8

9 Seeds/flower 15/10/2012 PSM 2011 r Metric S. cordifolium S. ericoides S. puniceum n R H' Late 2011 only 2011 n R H' n R H' PSM 2011 Best results obtained with S. puniceum, despite loss of one station... Closest correlation to pollinator richness (r 2 ~ 0.915) Pollinator Taxa Richness (#taxa/sample date) 9

10 Conclusions Bloom continuity, pollinator abundance and richness increase with age (quantitative analyses forthcoming!) (Anecdotal) resistance to drought? Improved drought resistance, bloom diversity and continuity priorities for management Conclusions Phytometric monitoring using seed set feasible, with carefully selected plant species Reduce cost, effort, and expertise necessary to assess pollination service Needs to address problems with drying, herbivory, variety of mating systems, cultural issues 10

11 PSM 2012 Currently underway, expanded to 10 plant species (from 3) 12 sites (from 5) Inclusion of zygomorphic flowers Citizen science pilot program (Seeds of Diversity/ Pollination Canada) with S. puniceum Special thanks to Rare Charitable Research Reserve, Environment Canada CESI, City of Guelph, Nelson Aggregates Field assistants E. Bowley, C. Dawson, L. Johnson, S. Morgan, D. Naylor, S. Parkes, L. Pekkola, J. Pomezanski, M. Tungate, Md. Hannan, A. McGraw-Alcock 11

12 Rare Charitable Research Reserve xxx Floral 2010 Bloom BFE GSF CCF Early Season Mid-Season 16* Late Season Total Insect Visits *dominated by Conyza canadensis 12

13 Floral 2012 Bloom BFE GSF CCF Early Season Mid-Season Late Season Total Insect Visits 2010 BFE GSF early June June & early July early July CCF late July July & early August August 13

14 Future work Connectance webs Pollinators vs. flower visitors, determination of important pollinators Assess resources vs. phenology of available flowers Rare Charitable Research Reserve Sampling of pollinator assemblages with pan traps (blue, yellow) and Malaise traps 14

15 Pollinator Assemblages Pan trap catches only (ANOVA of abundance, richness) Net catches Pollinator Assemblages 15