Health & Environmental Research Online (HERO)


Print Feedback Export to File
2895015 
Technical Report 
Visualization, Identification and Scaling of Complex Ecotoxicological Dynamics at Varying Physical and Temporal Scales 
Landis, WG; Matthews, RA; Matthews, GB 
1997 
NTIS/03002052 
GRA and I 
GRA and I 
We have developed and confirmed experimentally the Community Conditioning Hypothesis. The hypothesis states that impacts to ecological structures are persistent, the variables containing information change over time, and ecological systems are irreversible. We confirmed persistence of effects in experiments ranging from 90 to 180 days for 3-L microcosms to 240 days tor an outdoor mesocosm. Even wide differences in seasonal conditions or microclimate variation did not hide effects on larger systems. We conducted two types of experiments where microcosms were exposed to multiple stresses: (1) JP-8 stress was followed by heat shock and (2) two exposures 80 days apart to JP-8. For JP-8/heat, the initial stressor pattern was dominant with only minor changes in trajectory attributable to heat shock. For JP-8/JP-8, the second doing was dominant Thus. impacts due to multiple-stressor events can vary widely depending on timing and stress type. To aid analysts of effects at the community level, we developed a software package called MuSCLE that includes multivariate data analysis, pattern recognition, and visualization tools. We translated our results to the landscape level using metapopulation dynamic models. We found that impacts upon one patch can have dramatic effects upon other patches that are not contaminated.