Population dynamics of Apis mellifera -

Transcription

1 Population dynamics of Apis mellifera - an application of N-Mixture Models Adam Schneider State University of New York at Geneseo Eco-Informatics Summer Institute 2016

2 Apis mellifera 2015 Lookout Outcrop plant-pollinator network Apis mellifera Eriophyllum lanatum Gilia capitata Rumex acetosella 1

3 Research Question #1: How is the Apis mellifera population distributed spatially in the meadows and how is the population changing over time? Research Question #2: How is meadow fragmentation affecting the abundance of Apis mellifera in the meadows? 4

4 Field Methods - Exhaustive flower survey - 15 minute interaction watch per plot Lookout Main Complexes 4 Meadows per Complex R = 120 plots T = 5 watches 2

5 Field Methods Lookout Main - 15 minute interaction watch per plot - Interaction count = Pollinator visit PLOT Watch 1 Watch 2 Watch 3 Watch 4 Watch

6 Field Methods Lookout Main - 15 minute interaction watch per plot - Interaction count = Pollinator visit PLOT Watch 1 Watch 2 Watch 3 Watch 4 Watch

7 Generalized N-mixture model Hierarchical Model: State Model: N i ~ Negative Binomial(λ i, α) Observation Model: y i t ~ Binomial(N i, p i ) Covariates: log(λ i ) = x i,1 logit(p i ) = β 0 + β 1 x i,1 + + β T x i,t Open Population: Survivors: S i,t N i,t 1 ~ Binomial( N i,t 1, ω ) Recruits: G i,t N i,t 1 ~ Binomial γ N i,t 1 5

8 Generalized N-mixture model Hierarchical Model: State Model: N i ~ Negative Binomial(λ i, α) Observation Model: y i t ~ Binomial(N i, p i ) Covariates: Open Population: log(λ i ) = x i,1 logit(p i ) = β 0 + β 1 x i,1 + + β T x i,t Survivors: S i,t N i,t 1 ~ Binomial( N i,t 1, ω ) Recruits: G i,t N i,t 1 ~ Binomial γ N i,t 1 Population Estimate: N 1 = R λ N t = ω N t 1 + R γ 5

9 Model Selection Observational Covariates (OC): Total Flower Abundance (FLOW) Gilia Abundance (GIL) Eriophyllum Abundance (ERIO) Site Covariates (SC): Meadow (MEAD) AIC = 2 (# of Parameters) 2 ln L ln(l) = Log Likelihood of Model 6

10 Model Selection Observational Covariates (OC): Total Flower Abundance (FLOW) Gilia Abundance (GIL) Eriophyllum Abundance (ERIO) Site Covariates (SC): Meadow (MEAD) AIC = 2 (# of Parameters) 2 ln L ln(l) = Log Likelihood of Model 2012 MODEL # Parameters AIC SCORE OC = ERIO & GIL OC = GIL OC = FLOW SC = MEAD NULL_DIST = NB OC = ERIO NULL_DIST = POIS

11 Population Count RQ #1 Results: How is the interacting Apis mellifera population in the HJ Andrews Forest changing over time? Interaction Count Estimated Population YEAR 7

12 Estimated Apis Population RQ #2 Results: How is meadow fragmentation affecting the abundance of Apis mellifera in the meadows? R² = LS, LO, M2, RP1, RP2 High Apis mellifera abundance - Low Apis mellifera abundance R² = R² = R² = Distance to Meadows (km) MPI (at 1000 m) 8

13 Conclusions and Further Research 1. Interaction counts are an appropriate approximation for interacting population 2. Habitat fragmentation and loss of meadow habitat will have a negative effect on Apis mellifera 3. What contributes to the two distinct meadow groups? 4. Year-to-Year model with sub-watches would be very informative 9

14 Thank You, for all the Help and Support! Rebecca Hutchinson Julia Jones Kate Jones Andy Moldenke EISI PP TEAM and ( Dan & the RT ) Photo Credits: Slide 1 Carolyn Slide 2 Slide 3 Eddie Helderop Slide 4 Carolyn Slide 5 Carolyn & Emily 10

15 Population Parameters Mean λ Dispersion α Recruitment γ Survival ω