Hide and go seek: what does presence mean in the fossil record?
Our efforts to reconstruct accurate, complete records of events in vegetation history and in plant evolutionary history depend on accuracy in dating sediments, interpretation of structures preserved, reconstruction of whole organisms or communities from the preserved material, and interpretation of the interaction between past abundance and fossil presence. This contribution examines the interaction between past abundance of a target plant and the probability of retrieval of that species in the fossil record. By examining records of recolonization in volcanic areas, records of invasive species spread, succession in disturbed habitats, and historical migration patterns, we can provide estimates of the likelihood of appearance in the potential fossil record of newly evolved and reasonably successful species. The lag in discovery, recognition, and publication of a fossil as an important representative of a critical clade is also evaluated and is highlighted as a more important constraint on the use of fossils in testing evolutionary and ecological hypotheses than the recolonization rate. The lag between discovery and publication is particularly relevant in areas of the modern world where fossil plant-bearing deposits are either rare or inaccessible. Greater awareness of the density and reliability of the plant record should allow evolutionary biologists and paleoecologists to bracket not only time intervals but also geographic regions where the fossil record can be interpreted largely at face value. At the same time, more effort should be focused on intense collecting efforts and training in areas where fossil deposits are potentially present, but poorly collected and evaluated.