Question

The ability of models to make accurate predictions is limited by the scale of the system to which the model is applied compared to the scale for which the model was developed. This means that predictions about plant stomate responses to water stress in a greenhouse cannot apply to a clone of the same plant growing in a massive ecosystem.  

Is the above statement true or false? If false, explain why.

Answer 1

The statement above "predictions about plant stomatal responses to water stress in a greenhouse cannot apply to a clone of the same plant growing in a massive ecosystem" is FALSE.

This is because when we predict the behavior of any organism in artificial ecosystems like greenhouse or in lab conditions, we tend to provide similar conditions and hence observe the results. The difference in two lies in the sample size. If the model has been developed to study plant stomatal responses to water stress in a greenhouse, the conditions similar to those in actual ecosystem would be provided but the two will differ in the number of plants (i.e. sample size of the population under study). This just provides variation in the precision of the results. Large sample sizes do provide more precise results but actually there is a limit after which increase in sample size does not result in increased precision. More over working with large sample size is laborious as well as uneconomical. In greenhouse conditions, optimum sample size can be maintained which can work as a representative population of the massive ecosystem for the plant under study and can allow the predictions to be working in actual ecosystem. The only concern is that the result should be statistically significant i.e. in 95% confidence limit. The response should first be studied using a model and then can be taken to actual ecosystem to cross check the results. The models are very good indicators, provide speedy results and are economical. Directly working with massive ecosystem may or may not improve accuracy but even the small difference becomes significant.

So, the increase in sample size may or may not result in accurate observation. The small sized models like greenhouse can accurately predict the effect in field provided the similar conditions prevail in two systems. For studying water stress, the effect of unexpected rainfall in actual field can cause a problem with results in comparison to greenhouse model but that is not always the case. The models would be slightly different from actual conditions but are good indicators of a phenomenon.