Maxwell’s Research Interests

1. Maxwell’s Research Interests • Understand the driving processes that determine the dynamics of plant populations. • Are invasion and rarity any different? Same processes just change in predominance? • Are there threshold conditions for invasion and/or species loss? • What role does fire play in colonization or loss of plant species? Can fire make ecosystems more resilient or brittle? Anthropogenic fire vs lightning ignitions… • Does gain or loss of species behave the same at different time scales? 20 yr vs 5000 yr What processes are different at different time scales? • What are the climate implication for species colonization including direct and indirect relationships with fire…

2. Invasion Factors Invasive Traits Propagule Pressure Invasibility of New Environment Lockwood et al. 2005; Rejmánek et al. 2005; Barney and Whitlow 2008; Davis 2009

3. Stages of Invasion Radosevich et al. 2003 Naturalization Extrinsic factors K • Demographic stochasticity • Below minimum critical thresholds • Poor habitat • Competition with natives Colonization Intrinsic factors • Population vital rates • Phenotypic diversity • Habitat availability • Dispersal potential Introduction

4. Invasion Pressure Leung et al. 2004 Predicting invasions… Ecol. 85:1651-1660 Davis, 2009. Invasion Biology E = probability that at least one establishment will occur N = number of seed (propagules) p = probability of each seed establishing Invasion Pressure

5. Invasibility (p) could be increased by: • Increased resource availability due to disturbance (Davis et al. 2000) • Introduction or increase in abundance of an important mutualist (Richardson et al. 2000) • Enrichment with new arrivals of more fit phenotypes (Davis 2009) • Propagule pressure (N) could be increased by: • Year to year variability in growing conditions (good year) • Increased resource availability due to disturbance (Davis et al. 2000) • More or stronger vectors for dispersal (Cousens 2009) Nonlinearity in response to governing processes and conditions were also found using other models: Drake, 2004 Drake and Lodge, 2006

6. Population demographic variability (traits) Propagule pressure Habitat suitability Genetic variability (traits)

7. Cellular Automata Model λn λN

9. Uniform Environment Demographics Propagule pressure Phenotypic variability Dispersal

11. Northern Range Study Area 158,000 ha Elevation 2000 to 3500 m Lisa Rew, Patrick Lawrence Linariadalmatica

12. Change In Governing Processes Over Course Of Invasion 1970 1968 Linariadalmaticaintroduced ~1947

13. Predict NIS Probability Of Occurrence • Logistic Regression Model = • Resource Use Probability Function • Slope • Aspect • Elevation • Solar radiation • Wildfire, etc. NIS presence Determined best model using AIC Mapped Probability of Occurrence by Species (PO map) ≈ Habitat Suitability

14. L. Dalmaticanew colonies in 1970 (blue) Colonies that went extinct from 1968 to 1970 (pink)

15. Occupancy Model: Colonization = f(PO, Distance to nearest patch, Distance to Road) R Package Unmarked, MacKenzie et al 2006 Colonization rate Colonization rate Probability of Occurrence (habitat quality) Probability of Occurrence (habitat quality)

16. Occupancy Model: Extinction = f(PO, Distance to Road) R Package Unmarked, MacKenzie et al 2006 Extinctionrate Probability of Occurrence (habitat quality)

17. Methods 1970 1968 2001-2004 1947

18. 40 Years After Introduction

19. Idaho National Laboratory Predicting Distribution and Metapopulation Dynamics of Invasive and Rare Plant Species Lisa Rew, Matt Lavin and Tyler Brummer

20. Sisymbriumaltissimum

21. Occupancy Model: Colonization = f(PO, Fire, Distance to nearest patch, Distance to Road) R Package Unmarked, MacKenzie et al 2006

22. Occupancy Model: Extinction = f(PO, Fire, Distance to Road) R Package Unmarked, MacKenzie et al 2006

23. Coupled Natural Human Systems Proposed Project (NSF) Andy Hansen, Katie Suding, Michael Brody, Liz Shanahan, Derek Robinson Figure 1. Conceptualization of the exurban CNHS. Feedbacks within and among different components and at different scales create complex dynamics at the landowner-wildlands interface. Our three overarching questions focus on the interactions among components leading to more sustainable ecosystem management. Figure 4. Map of the study area and location in the Greater Yellowstone ecosytem.

24. The goal of this study is to better understand the interactions between exurban residents and local ecosystems and the potential for these communities to be uniquely able to sustain both ecological and human values . Key questions are: How important are NA to exurban resident’s perception of wellbeing at the home site and to their property management behaviors relative to traditional social, economic, and cultural factors? What are the effects of exurban development on ecosystem properties that provide NA, specifically, the structure and composition of plant and bird communities? To what extent does informal environmental education cause exurban residents to increase their valuation of NA and modify their property management behaviors to be more sustainable? Dynamics Over Time

25. Figure 8.Map of virtual exurban development with patches of relatively high invasive species PO corresponding with an access road/driveways and house sites and an initial population (red pixel) established along the road. The model simulates invasion along the road and into house sites. In addition, there is an agent based portion (2 dogs = black dots) that increase dispersal of invasive plant species.