Synthesizing information for the environmental sciences |
Potential from emerging tools | |
Jim Clark | |
Nicholas School of the Environment | |
Department of Biology | |
Department of Statistical Science |
Example: the climate change puzzle |
Uncertain climate predictions | |
Complicated patterns in ecological data |
Models of current climate |
Precipitation (control runs) | ||
Convective storms | ||
Multiple moisture sources (Gulf, Atlantic) | ||
Location and strength of: | ||
Bermuda High | ||
Nocturnal jet | ||
Hurricane moisture in summer | ||
Models of future climate |
2 x CO2 Precip | |
Dry winter, summer |
Models of future climate |
hot |
Models of response |
SE aridity and savanna expansion |
Models of response |
Climate change impacts on species | ||
Based on climate envelopes | ||
Correlations with long-term averages | ||
Plants respond to weather | ||
Future climates will be novel | ||
Ignore subgrid processes |
Source of immigrants? |
Source of immigrants? |
Biodiversity responds to spatial heterogeneity |
Subgrid processes: | ||
Growth and survival respond to gaps |
Seed has limited production and dispersal |
Varies by species |
What do ÔprocessÕ data say? |
Residents vs potential invaders |
Could coastal plain spp invade the Piedmont? | |
Could Piedmont spp invade the S. Appalachians? | |
Relative demographic performance of residents vs potential invaders? |
Seedling germination |
Seedling growth rates |
Seedling survival |
Process data climate correlations |
No advantage to potential invaders for any demographic rate in any local habitat | |
Complex | |
WhatÕs missing? |
Challenges |
How will each species respond to changing climate, in the context of environmental variation? | |
Differential responses with size and age | |
Causal factors multiscale, interact | |
Causal factors and responses partially observed. |
Outline |
Prediction framework | |
Assimilating models and data |
Outline |
Prediction framework | |
Assimilating models and data |
Prediction framework |
X,y data | |
M model | |
qM parameters | |
XÕ scenario | |
yÕ prediction | |
Outline |
Prediction framework | |
Assimilating models and data |
Our approach |
Long-term demographic monitoring (1991-) | ||
Experiments | ||
Individuals to small plots to landscapes | ||
Intervention designs | ||
Manipulate environment | ||
Introduce potential immigrants | ||
Detailed environmental data | ||
Hierarchical modeling to | ||
Integrate all sources of information | ||
Accommodate the unknowns |
Long term, heterogeneous data |
Mapped stands | ||
All life history stages | ||
Seed rain | ||
Seed banks | ||
Seedlings | ||
Saplings | ||
Mature trees | ||
Interventions | ||
Canopy gaps | ||
Nutrient additions | ||
Herbivore exclosures | ||
Fire | ||
Environmental monitoring | ||
Canopy photos | ||
Soil moisture | ||
Temperature | ||
Wireless sensor networks | ||
Remote sensing |
Heterogeneous data |
Simulator for analysis/prediction |
Missing the connections |
Hierarchical Bayes model |
Light availability: ground to remote data |
Ground measurements |
Remote sensing |
Exposure to sky |
Solar geometry models |
Estimates combine three data types |
What makes this possible? |
Inference |
State space model: Fixed and random individual effects |
Inference |
Maturation status |
Inference |
Seed prediction from estimated fecundity |
Inference |
Seed prediction from estimated fecundity |
Estimates of hidden states |
Sources of variability/uncertainty in fecundity |
Inference |
Semiparametric mortality |
Mortality risk with size, growth rate |
Allocation: among individuals |
Many estimates |
27 parameters for growth, fecundity, and associated process and observation errors | |
T fixed year effects | |
40 mortality risk estimates (34 growth rate classes, 6 diameter classes) | |
2n random effects (growth and fecundity) | |
5nT latent states (canopy area, diameter, fecundity, maturation status, mortality risk) | |
n > 103 trees | |
T = 16 years (1992 – 2007) | |
Slide 45 |
Slide 46 |
Prediction framework |
X,y data | |
M model | |
qM parameters | |
XÕ scenario | |
yÕ prediction | |
The implications: Scalable Landscape Inference & Prediction (SLIP) |
Prediction that incorporates sources and scales for knowns and unknowns | |
How to be efficient? |
SLIP Light Model |
Light computation explicit each m2 | |
Individual trees | |
Graphics hardware based algorithm |
Detail where it matters |
SLIP Dispersal Algorithm |
Forward simulation: individuals respond to landscape influences |
Competitive exclusion |
with random effects |
The advantages of multilevel modeling |
Fully exploit data through coherent assimilation | |
Synthesis of all information | |
Predictions follow directly from estimates |
The challenges |
Modeling: When is complexity warranted? | ||
Abundant, heterogeneous data | ||
Products important | ||
Repeated application, e.g, spp, sites, intervals | ||
Ex: software for broad use, dissemination; NWP | ||
Doing the computation | ||
Efficient algorithms, data structures |
Collaborators |
Lab participants: | ||
Brian Beckage (Univ Vermont) | ||
Jim Clark | ||
Mike Dietze | ||
Janneke HilleRisLambers (Univ Washington) | ||
Ines Ibanez | ||
Shannon LaDeau (Smithsonian Inst) | ||
Allen McBride | ||
Jason McLachlan (Notre Dame Univ) | ||
Jackie Mohan (Harvard Univ) | ||
Mike Wolosin | ||
Pete Wykoff (Univ Minnesota) |