This emerging view suggests that the effects of acid rain are more complex than expected and that the damage caused by the pollution is more serious than predicted. It is entirely feasible that continuing acid rain, in combination with limited supplies of base cations, could produce environmental conditions to which many plant species, particularly in sensitive ecosystems, have never been exposed in the course of their evolution. Consequently, predicting how they will respond over the next several decades will be extremely difficult. And effects may not be limited to plants. Jaap Craveland and his colleagues at the University of Groningen, have noted that certain birds, such as the great tits of the Netherlands produce thinner, more fragile eggs in forests that have been heavily damaged by acid rain and have low stores of calcium in the soil.
Suggestions range from the improbable to the feasible.
Deliberate increases in the release of particulates are also unrealistic and would set back progress in air pollution control by decades. In the meantime, researchers and governments must develop careful strategies not only for monitoring the current health of forests but also for predicting their stability in the next century and beyond. Simple solutions do not always work in complex ecosystems.