Abstract
Based on an electronic database of 9 million 1 sq km plant records from 1902-1999, collected in three successive periods, we want to examine which changes in taxic diversity have taken place and what we can expect to happen in the near future. We will concentrate our study on c. 300 declining scarce & rare species and c. 150 increasing species (including invasive ones), with special attention on their biological characters (e.g. life cycle strategy, soil seed bank strategy, dispersal strategy) of the 450 selected species (out of 1450 standard list species). We expect to be able to predict which species are endangered because of dispersal problems and which may be revitalized from the soil seed bank. Getting a complete list of the new-comers and increasing species, we can calculate their contribution to the total biodiversity. It will also be possible to estimate the effectiveness of various measures in nature policy in the Netherlands. The study will provide a firm basis for the calibration of the results of the (proposed) national flora monitoring programs.
Netherlands